Centrifugal governor, particularly for varying the timing of ignition



Nov. 7, 1950 1' e LOUIS 2,528,698

CENTRIF'UGAL GOVERNOR, PARTICULARLY FOR VARYING THE TIMING 0F IGNITION Filed Nov. 27, 1948 2 Sheets-Sheet 1 IIYSl/L A no INVENTOR 7203mm: 6.10am

Nov. 7, 1950 T s LOUIS 2,528,698

CEN'I'RIFUGAL GOVERNOR, PARTICULARLY FOR VARYING THE 'rmmc 0F IGNITION 2 Sheets-Sheet 2 Filfld NOV. 27., 1948 INVENTOR JZ'RRENCE 6.110015 BY a6 ATTORNZS Patented Nov. 7, 1950 CENTRIFUGAL GOVERNOR, PARTICULARLY FOR VARYING THE TIMING F IGNITION Terrence G. Louis, West Springfield, Mass., assignor to Wico Electric Company, West Springfield, Masa, a corporation of Massachusetts Application November 27, 1948, Serial No. 62,388

2 Claims. 1

This invention relates to improvements in centrifugal governors, which are particularly adapted for use in varying the timing of the ignition relative to the operation of an internal combustion engine. The governor may be used to provide for retarded ignition on starting the engine and at relatively low engine speeds and for advanced ignition at higher speeds.

The invention has for one object to provide an improved governor construction, made up of a small number of simple parts, easily manufactured and assembled by simple methods, whereby the construction is capable of being manuiactured in quantities at low unit cost.

The invention has for another object the provision of a governor construction, wherein compression coil springs are utilized to move the weight levers against the action of centrifugal force and wherein these springs are located with their axes in a plane passing centrally through the levers at right angles to their pivotal axes, whereby to avoid lateral thrust of the springs on the levers.

The invention has for a further object to provide an improved governor construction, wherein the weight levers are held to their supporting plate against any substantial axial movement by means of links, each of which connects a fulcrum of one lever to a stud on the weighted portion of the other lever, each such stud riding in a slot in its link and such stud and slot limiting the extent of swinging movement of the weight levers.

These and other objects will best be understood from the detailed description of one illustrative example of the invention in the accompanying drawings, in which:

Fig. l is a side elevational view, with parts in section, of an ignition unit embodying the invention;

Fig. 2 is a fragmentary cross sectional view taken on the line 2-2 of Fig. 1 and showing the breaker mechanism of the ignition unit;

Fig. 3 is an enlarged cross sectional view taken on the line 3-3 of Fig. 1 and showing the speedresponsive mechanism;

Figs. 4 and 5 are front and side elevation views respectively of the plate that carries the weight levers of the speed-responsive mechanism;

Fig. 6 is a front elevational view of one of the weight levers;

Fig. 7 is a front elevational view of a weight part for a weight lever;

Fig. 8 is a sectional view taken on the line 8-8 of Fig. 3; and

P18. 9 is a bottom plan view of the speed-responsive mechanism shown in Fig. 3.

Referring to these drawings; the speed-responsive mechanism is shown herein in one embodiment which is adapted for use in an ignition system for internal combustion engines to change the angular relation between an engine-driven shaft and the actuating cam of a breaker mechanism, together with the rotor of a distributor, when one is required, for the purpose of varying the timing of the ignition of the ignition sparks.

In Fig. 1, a metallic casing I, adapted for fastening to an engine crankcase, has rotatably mounted therein in bearings 2 a driving shaft 3, which is adapted to be driven by the engine in any suitable way, as by means of the coupling part I. The casing I contains a breaker mechanism best shown in Fig. 2 and including a cam 5, a breaker-arm 6 of insulating material, which is pivoted on a stud I, carried by a supporting plate 8 and which carries a breaker point 9, and a stationary breaker point It) for cooperation with point 9 and suitably fixed to plate '8. The latter is circular and fits into seats in the casing I, being held therein by screws H. The plate is thus grounded, as is the breaker point II], which is fixed thereto. The breaker point 9 is connected by a spring l2 to an insulated terminal l3, which is mounted on plate 8 and is adapted for connection to the primary winding of an ignition coil. The spring l2 holds one end of the breaker arm 6 against its actuating cam 5 and tends to maintain the breaker points 9 and I0 engaged. The cam 5 (Fig. 1) is formed integrally with a hollow cylindrical shaft M, which is rotatable on a part l5of reduced diameter of shaft 3 and which is adapted for connection to the speedresponsive mechanism in a manner to be later described.

The casing I has attached thereto a distributor housing l6 of insulating material in which are mounted the usual circular series of terminals ll which are adapted for connection to'wires lead- I ing to the spark plug of the engine. A rotor ll of insulating material is rotatably mounted on a stud l9 fixed in casing l and carries a radial finger 20, which is connected at its inner end to a central carbon block 2| mounted in the rotor. The block 2| is engaged by a spring 22 on housing l6 and this spring is adapted for connection to the secondary winding of the ignition coil.

The outer end of finger 20 is adapted to distrib-' ute the high tension current successively to the terminals 11 in the usual manner. The distributor rotor has formed thereon a gear 23 which meshes with a pinion 24 fixed to the outer end of the shaft part M.

The driving shaft 3 and the hollow cam shaft M are connected together by the speed-responsive mechanism of this invention as best shown in Figs. 3 and 8. The shaft 3 has fixed thereto at right angles to its axis a thin flat plate 25 (shown separately in Figs. 4 and 5), and this plate has a central circular portion slightly larger in diameter than the shaft I4 (Fig. 3) and two diametrically-opposed and relatively-narrow radial extensions which carry, one near the outer end of each, a fulcrum stud 2B riveted to the plate (Fig. 8). The shaft 3 is reduced in diameter where it passes through the center of plate 25, formin a shoulder, against which one flat face of the plate seats and the parts are suitably held together, as for example by forcing part of the shaft over against the plate as indicated at 21. The hollow shaft M (Fig. 8) telescopes over the shaft part l5 and terminates with its inner end face against the central portion of the other flat face of plate 25. There are two slots 28 (Fig. 3) in the inner end of shaft |4 located at diametrically opposite points. The plate is connected to shaft M by a two weight levers of bellcrank form. Each such lever is pivotally mounted, at a point intermediate the two arms thereof, on a fulcrum stud 26. The short arm 29 of each lever has a rounded end that closely fits in one of the slots 28 of shaft M. The long arm 30 has an enlarged part 3| to which is fixed by rivets 32 and 33 a similar part 34 (see also Fig. 9), and these parts form a weight adapted to be moved outwardly by centrifugal force, rocking the levers clockwise and moving shaft l4 counterclockwise ahead of shaft 3.

The weight levers (Fig. 3) are limited in their outward swinging movement by links 35. Each link at one end has a hole to fit a fulcrum pin 26 and the inner face of such end lies against the outer face of the weight lever and is held from outward movement on the pin by means of a retaining clip 36, which is engaged in a circumferential groove 31 in the fulcrum pin. The fulcrum end of each weight lever is thus held in place between plate 25 and link 35. Each link, which is pivoted at one end to one bellcrank lever, has its other end overlying the weight portion 3| of the other bellcrank lever and a stud 38, fixed to such portion 3|, rides in a longitudinal slot 39 in the link. This stud serves as the head of the described rivet 33. A thin fiat head 40 on stud 38 serves to hold the link in place. Each bellcrank lever is thus held at two points by the two links 35, one point being near the fulcrum of the lever and the other point being near the outer end of the long arm 30 of the lever. The head 40 is roughly rectangular with parallel sides, the dis-' tance between which is less than the width of slot 39. The length of the head is greater than the width of the slot, and when the parts are assembled, the head lies crosswise of the link to retain the same in place. However, when the link is disconnected from its fulcrum pin 26, it may be turned until the parallel sides of the head lie lengthwise and parallel with the sides of the slot when it can be moved past such head. The length of slot 39 determines the extent of angular movement of the weight levers. They may move outwardly by centrifugal force until the stud 38 abuts the outer end of slot 39. When the weight levers move inwardly, by spring means to be described, the stud 33 will abut the inner end of its slot 39 and limit the extent of inward movement of the weight lever.

The sprin means for moving the weight levers inwardly comprise compression coil springs 4|, one for each lever. Each weight lever has formed in its outer edge a seat 42 for one end of a spring 4| and such seat has a rounded protuberance 43 which enters inside the spring and prevents it from moving laterally on the seat. The plate 25 has two arms 44, struck up therefrom, one adjacent each fulcrum stud 26. One edge 45 of each arm 44 forms a seat for the other end of a spring 4|. This seat 45 has a rounded protuberance 46 which enters inside the spring and prevents it from lateral movement on the seat. The springs 4| tend to hold the bellcrank levers in their innermost positions. The shaft 3 rotates clockwise, as viewed in Fig. 3. At low engine speeds, the weight levers are held in their inner positions by the springs 4| and the timer and distributor will then be in positions for retarded ignition. As the engine speed increases, the weighted levers will be moved outwardly (clockwise as viewed in Fig. 3) by centrifugal force and the arms 29 will turn the hollow shaft |4 counterclockwise and thus shift the breaker cam 5 and distributor rotor I8 into positions for advanced ignition.

The governor construction described is simple and its parts are inexpensive to make and may be easily assembled, so that the construction may be manufactured in quantities at low unit cost. The plate 25 is a stamping and the holes therein for the shaft 3 and the studs 26 may be punched out at the same time that the plate is stamped out. The weight carrying levers and the weight parts 34, including the holes therein, may be formed in a punch press. The links 35 and their slots and holes may be similarly formed. The studs 26 are riveted to the plate 25 and the parts 3| and 34 are secured together by the rivets 32 and 33. The plate 25 is brazed to shaft 3. The spring 4| are simply cut to length from standard stock. They simply have square ends. No hooks or loops are necessary, as in tension springs, and no holes need to be drilled in the weights and plate to receive such hooks or loops. No finishing whatever is required of the governor parts except for the driving and driven shafts. The various governor parts can be easily and rapidly assembled without the use of any tools. One places the weight-carrying levers on their studs 26. Then each link 35 is applied by first positioning it so that the sides of its slot 39 parallel the long parallel edges of the head 40 and then passing the link over head 40, after which the link is turned until the hole therein can be passed over the nearest fulcrum stud 26. A standard retaining clip 36 is then pressed into the groove 31 of each stud 26 and the assembly is complete except for the springs 4|. These are easily and quickly put in place by hand. One places one end of a spring 4| over the protuberance 43 and compresses the spring until the other end can he slipped over the protuberance 43. The entire assembly takes less than a minute. The use of coil springs instead of the usual tension springs aids in cutting the cost of manufacture because the compression spring itself is much cheaper than a tension spring and because it can be assembled more quickly.

These compression springs are however important for another reason. They enable each spring to be located with its axis in a plane which passes centrally through the lever at right angles to the axis of its fulcrum so that the force of the spring is exerted on the lever all in this one plane for effecting swinging movement of the lever without producing any lateral thrust on the lever from the spring. This makes for smoother action of the governor and longer life through lessened wear on the parts. The governor will function well even when constructed of parts which are not finished and where the tolerances necessarily have to be greater than they would be if the parts were finished.

The arrangement, whereby the links, which limit the throw of the weight-levers, alsoact to hold these levers to their supporting plate against undue lateral movement, is also thought to be important. Each link at one end overlies the fulcrumed part of one weight lever and is pivoted on the fulcrum stud 26 and at the other end overlies the weighted portion of the other lever. The clip 36 and head 40 hold the link in place.

The invention thus provides an improved governor which, while capable of other uses, is particularly suitable for use in varying the timing of ignition in an internal combustion engine in response to changes in engine speed.

I claim:

1. A centrifugal governor, comprising, a rotatable driving shaft, a plate fixed to said shaft and having a flat face at right angles to the axis of the shaft, a plurality of fulcrum pins fixed to the plate and projecting from said face with their axes parallel with the axis of rotation of the plate, said pins being located in equal angular spaced relation about the axis of rotation of the plate, weight levers pivotally mounted one on each fulcrum pin for swinging movement in a plane parallel with said face and adapted to be swung outwardly by centrifugal force when said shaft exceeds a certain speed, each lever having an inner face parallel with and closely adjacent to said face of said plate, springs acting between the plate and levers for moving such levers inwardly, links pivotally connected at one end one to each fulcrum pin, each link having the inner face of its pivoted end closely adjacent to the outer face of the fulcrumed portion of one lever and extending across the weight portion of the other lever with its inner face in parallel and closely adjacent relation with the outer face ofsuch lever, each link having a longitudinal slot therein, a stud fixed to the weighted part of each lever and extending into said slot, said stud being operable by abutment with the inner and outer ends of said slot to respectively limit the inward and outward movement of said levers, a device on the outer end of each fulcrum pin to retain the link and lever thereon and prevent undue axial movement thereof, a head on each stud to restrain the link through which it passes against undue axial movement, a driven shaft coaxial with the drivingshaft, and connections between said weight levers and driven shaft for driving the driven shaft through said levers and for shifting the driven shaft angularly relatively to the driving shaft as the weight levers move in and out accordingly as the speed of the driving shaft respectively falls below or exceeds said certain speed.

2. A centrifugal governor, comprising, a rotatable driving shaft, a plate fixed to said Shaft and having a flat face at right angles to the axis of the shaft, a plurality of fulcrum pins fixed to the plate and projecting from said face with their axes parallel with the axis of rotation of the plate, said pins being located in equal angular spaced relation about the axis of rotation of the plate, weight levers pivotally mounted one on each fulcrum pin for swinging movement in a plane parallel with said face and adapted to be swung outwardly by centrifugal force when said shaft exceeds a certain speed, each lever having an inner face parallel with and closely adjacent to said face of said plate, springs acting between the plate and levers for moving said levers inwardly, links pivotally connected at one end one to each fulcrum pin, each link having an inner face of its pivoted end closely adjacent to the inner face of the fulcrumed portion of one lever and extending across the weight portion of the other lever with its inner face in parallel and closely adjacent relation with the outer face of such lever, each link having a longitudinal slot therein, a stud on the weighted part of each lever extending into said slot and operable by abutment with the inner and outer ends of said slot to respectively limit the inward and outward movement of said levers, a device on the outer end of each fulcrum pin to retain the link and lever thereon and prevent undue axial movement thereof, a head on each stud to restrain the link through which it passes against undue axial movement, a driven shaft coaxial with the driving shaft, and connections between said weight levers and driven shaft for driving the driven shaft through said levers and for shifting the driven shaft angularly relatively to the driving shaft as the weight levers move in and out accordingly as the speed of the driving shaft respectively falls below or exceeds said certain speed, said head having a length greater than the width of said slot and a width less than the width of said slot, said head normally having its long dimension located approximately crosswise of the slot to restrain the link against undue axial movement, said link when removed from its fulcrum pin after said device is removed from the latter being turnable to carry the sides of its slot into parallel relation with the long dimension of said head to enable the head to pass through said slot and the link to be removed from its stud.

TERRENCE G. LOUIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 771,771 Dysterud Oct. 4, 1904 1,231,586 Foot July 3, 1917 1,257,630 Newton Feb. 26, 1918 FOREIGN PATENTS Number V Country Date 522,066 France 1921 425,240 Germany 1926 

